Deformation behavior of an epoxy resin subject to multiaxial loadings. Part II: Constitutive modeling and predictions

• Published in: Polymer engineering and science Vol. 43; no. 3; pp. 734 - 748
• Main Authors: Xia, Zihui, Hu, Yafei, Ellyin, Fernand
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.03.2003; Wiley Subscription Services; Society of Plastics Engineers, Inc; Blackwell Publishing Ltd
• Subjects: Applied sciences; Epoxy resins; Exact sciences and technology; Measurement; Mechanical properties; Physical properties; Polymer industry, paints, wood; Properties and testing; Technology of polymers; Viscoelasticity; Compressive stress; Tensile stress; Creep; Stress strain relation; Non linear viscoelasticity; Mechanical properties; Shear stress; Epoxy resin; Experimental study; Multiaxial load; Modeling
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.10061

Based on the experimental data presented in Part I, a nonlinear viscoelastic constitutive model, in differential form, is presented here. A distinctive feature of this model is the inclusion of a criterion to delineate loading and unloading in multiaxial stress states, and different moduli for loading and unloading behaviors. In addition, the model contains only five material constants and one modulus function, which can be calibrated in accordance with a well‐defined procedure. A comparison with the experimental data shows that the current differential model is capable of predicting the nonlinear viscoelastic behavior of the epoxy polymer qualitatively and quantitatively, including both the loading and unloading behavior. The predictions of an integral form of constitutive model are also included for comparative purposes.